Solve Addition and Subtraction Problems using Written Methods

In this activity, we are going to look at using a written method to help us solve addition and subtraction questions. 

Example 1 

32 + 12 = 

Let's have a look at a written method to help us solve this.

We can draw pictures to represent the tens and ones to help us work it out. 

For 32 we have drawn 3 red lines to show the 3 tens in 32 and 2 dots to show the 2 ones. 

For 12 we have drawn 1 red line to show the 1 ten in 12 and the 2 dots to show the 2 ones. 

Now, we can use these pictures to help us add it all together. 

If we now draw all the tens together and all the ones together, we can count them all up to get our answer. 

There are 4 red lines, this is 4 tens which give us 40. 

Then there are 4 ones to add on, 40 + 4 = 44

So this is how we can use drawing pictures of tens and ones to help us solve addition questions. 

Example 2 

48 - 12 = 

Let's have a look at a written method to help us solve this.

We can draw pictures, lines or letters to represent the tens and ones to help us work it out.

For subtraction, we only need to draw out the tens and ones for the first number. 

Here we have 4 tens and 8 ones to make 48. 

T T T T  oooooooo

As we are taking away, we need to take away 12 from 48. 

So we need to take away 1 ten and 2 ones - we have crossed them off. 

T T T T  oooooooo

To find the answer, we just need to count how many tens and ones are left!

There are 3 tens and 6 ones, so this means we have 36 left. 

48 - 12 = 36

Go and grab yourself a pencil and paper and you can use this written method to answer these questions.